The advent of "smart" circuit interrupters, such as that described within U.S. Pat. No. 4,672,501 which Patent is incorporated herein for reference purposes, permits several such circuit interrupters to be arranged within a common enclosure, all interconnected with a central processor unit. The central microprocessor within the central processor unit, in turn, communicates with each of the circuit interrupters within the common enclosure for enhanced protection of the associated electrical equipment. The central processor unit continuously interrogates each of the interconnected circuit interrupters to determine the status of the individual circuit interrupter setpoint parameters as well as whether the circuit interrupter has responded to interrupt circuit current to an associated piece of electrical equipment. An operator could then readily determine from the central processor unit which of the interconnected circuit interrupters has responded and could also determine the nature and magnitude of the overcurrent condition causing the circuit interrupter to respond.
In certain industrial environments, it is customary to assemble a main circuit interrupter along with several branch circuit interrupters within a common enclosure such as within low voltage switchgear applications. A central processor, hereafter "field programming unit" is arranged within the enclosure and is electrically interconnected with the main and branch circuit interrupters to determine the condition and status of the circuit interrupter and protected electrical equipment. In order to address a particular branch circuit interrupter, each branch circuit interrupter is assigned a name which is stored within the field programming unit. When the branch circuit interrupter is summarily addressed by a name, the field programming unit displays the status and condition of the addressed circuit interrupter to ascertain the corresponding status. Oftentimes, the circuit interrupters are interchanged within the enclosure such that the operator is no longer able to determine the status and condition of associated electrical equipment by addressing a named circuit interrupter.
One purpose of this invention is to provide a system whereby the particular circuit interrupter addressed by the field programming unit provides positive indication that the particular circuit interrupter at a given address is in fact the correct circuit interrupter responding to the status and condition request of the field programmer unit.